Rebuilding the recycler view causes it to disappear

In my code, I am building a recycler view, via the methodsetUpRecyclerView(country);, when my fragment is fast created and later on I call the same method (or various other methods that build a recycler view e.g.setUpRecyclerViewWithKeyword(country, search_key); , setUpRecyclerViewWithPreferences(country, anime, art, edu, gaming, music, other); , setUpRecyclerViewWithKeywordAndPreferences(country, search_key, anime, art, edu, gaming, music, other); ) to build the recyler view again. This is illustrated below:

My Fragments OnViewCreated code

  public void onViewCreated(View view, Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);
final String id = FirebaseAuth.getInstance().getCurrentUser().getUid();
search_keyword = getView().findViewById(R.id.exp_search);
search_btn = getView().findViewById(R.id.exp_search_btn);
ccp = getView().findViewById(R.id.exp_ccp);
refresh = getView().findViewById(R.id.refresh);
country = ccp.getSelectedCountryName();
setUpRecyclerView(country);
Log.e("explore frag","1");
db.collection("Users").document(id).collection("preferences").document("event").get().addOnCompleteListener(new OnCompleteListener<DocumentSnapshot>() {
@Override
public void onComplete(@NonNull Task<DocumentSnapshot> task) {
if (task.isSuccessful()) {
DocumentSnapshot documentSnapshot = task.getResult();
if (documentSnapshot.exists()) {
String anime = documentSnapshot.get("anime").toString();
String art = documentSnapshot.get("art").toString();
String edu = documentSnapshot.get("edu").toString();
String gaming = documentSnapshot.get("gaming").toString();
String music = documentSnapshot.get("music").toString();
String other = documentSnapshot.get("other").toString();
String all = documentSnapshot.get("all").toString();
String search_key = search_keyword.getText().toString().trim();
country = ccp.getSelectedCountryName();
if (all.equals("1") && TextUtils.isEmpty(search_key)) {
setUpRecyclerView(country);
Log.e("explore frag","2");
} else if (all.equals("1") && !(TextUtils.isEmpty(search_key))) {
setUpRecyclerViewWithKeyword(country, search_key);
Log.e("explore frag","3");
} else if (all.equals("0") && TextUtils.isEmpty(search_key)) {
setUpRecyclerViewWithPreferences(country, anime, art, edu, gaming, music, other);
Log.e("explore frag","4");
} else {
setUpRecyclerViewWithKeywordAndPreferences(country, search_key, anime, art, edu, gaming, music, other);
Log.e("explore frag","5");
}
}
}
}
}).addOnFailureListener(new OnFailureListener() {
@Override
public void onFailure(@NonNull Exception e) {
}
});
adapter.setOnItemClickListener(
new ExplorePageAdapter.OnItemClickListener() {
@Override
public void OnItemClick(DocumentSnapshot documentSnapshot, int position) {
String id = documentSnapshot.getId();
Intent intent = new Intent(getActivity(),
event_customer_view_activity.class);
intent.putExtra("Event_ID", id);
startActivity(intent);
//   getActivity().finish();
}
}
);
}

RecylerView building method

   private void setUpRecyclerView(String country) {
Log.e("explore frag",country);
Query query = Cref.whereEqualTo("country", country);
FirestoreRecyclerOptions<POJO_explore_page_item> options = new
FirestoreRecyclerOptions.Builder<POJO_explore_page_item>()
.setQuery(query, POJO_explore_page_item.class).
build();
adapter = new ExplorePageAdapter(options);
RecyclerView recyclerView = getView().findViewById(R.id.explore_recycler);
//        recyclerView.setAdapter(null);
//        recyclerView.setLayoutManager(null);
//        recyclerView.getRecycledViewPool().clear();
recyclerView.setHasFixedSize(true);
recyclerView.setLayoutManager(new LinearLayoutManager(getActivity()));
recyclerView.setAdapter(adapter);
}

My problem is that whenever I try to rebuild the new recycler view, there is no result unllke the first time the recyler view is built. It is almost as though the recycler view disappeares.

Attempted solutions:

I have tried adding recyclerView.setAdapter(null); andrecyclerView.setLayoutManager(null); before

  recyclerView.setLayoutManager(new LinearLayoutManager(getActivity()));
recyclerView.setAdapter(adapter);

I have also tried rebuilding the recyler view in my OnViewCreated method

    public void onViewCreated(View view, Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);
final String id = FirebaseAuth.getInstance().getCurrentUser().getUid();
search_keyword = getView().findViewById(R.id.exp_search);
search_btn = getView().findViewById(R.id.exp_search_btn);
ccp = getView().findViewById(R.id.exp_ccp);
refresh = getView().findViewById(R.id.refresh);
country = ccp.getSelectedCountryName();
//setUpRecyclerView(country);
///
Log.e("explore frag",country);
Query query = Cref.whereEqualTo("country", country);
FirestoreRecyclerOptions<POJO_explore_page_item> options = new
FirestoreRecyclerOptions.Builder<POJO_explore_page_item>()
.setQuery(query, POJO_explore_page_item.class).
build();
adapter = new ExplorePageAdapter(options);
final RecyclerView recyclerView = getView().findViewById(R.id.explore_recycler);
recyclerView.setHasFixedSize(true);
recyclerView.setLayoutManager(new LinearLayoutManager(getActivity()));
recyclerView.setAdapter(adapter);
///
Log.e("explore frag","1");
db.collection("Users").document(id).collection("preferences").document("event").get().addOnCompleteListener(new OnCompleteListener<DocumentSnapshot>() {
@Override
public void onComplete(@NonNull Task<DocumentSnapshot> task) {
if (task.isSuccessful()) {
DocumentSnapshot documentSnapshot = task.getResult();
if (documentSnapshot.exists()) {
String anime = documentSnapshot.get("anime").toString();
String art = documentSnapshot.get("art").toString();
String edu = documentSnapshot.get("edu").toString();
String gaming = documentSnapshot.get("gaming").toString();
String music = documentSnapshot.get("music").toString();
String other = documentSnapshot.get("other").toString();
String all = documentSnapshot.get("all").toString();
String search_key = search_keyword.getText().toString().trim();
country = ccp.getSelectedCountryName();
if (all.equals("1") && TextUtils.isEmpty(search_key)) {
//  setUpRecyclerView(country);
Query query = Cref.whereEqualTo("country", country);
FirestoreRecyclerOptions<POJO_explore_page_item> options = new
FirestoreRecyclerOptions.Builder<POJO_explore_page_item>()
.setQuery(query, POJO_explore_page_item.class).
build();
adapter = new ExplorePageAdapter(options);
recyclerView.setAdapter(null);
recyclerView.setLayoutManager(null);
recyclerView.setHasFixedSize(true);
recyclerView.setLayoutManager(new LinearLayoutManager(getActivity()));
recyclerView.setAdapter(adapter);
Log.e("explore frag","2");
} else if (all.equals("1") && !(TextUtils.isEmpty(search_key))) {
setUpRecyclerViewWithKeyword(country, search_key);
Log.e("explore frag","3");
} else if (all.equals("0") && TextUtils.isEmpty(search_key)) {
setUpRecyclerViewWithPreferences(country, anime, art, edu, gaming, music, other);
Log.e("explore frag","4");
} else {
setUpRecyclerViewWithKeywordAndPreferences(country, search_key, anime, art, edu, gaming, music, other);
Log.e("explore frag","5");
}
}
}
}
}).addOnFailureListener(new OnFailureListener() {
@Override
public void onFailure(@NonNull Exception e) {
}
});
adapter.setOnItemClickListener(
new ExplorePageAdapter.OnItemClickListener() {
@Override
public void OnItemClick(DocumentSnapshot documentSnapshot, int position) {
String id = documentSnapshot.getId();
Intent intent = new Intent(getActivity(),
event_customer_view_activity.class);
intent.putExtra("Event_ID", id);
startActivity(intent);
//   getActivity().finish();
}
}
);
}

Neither of these two attempts worked. Any suggestions?

Solution

As @just_user's second comment on my original post implies, I have to call adapter.stopListening() before I create a new adapter. Afterwards, I can call adapter.startListening().This is illustrated below:

    @Override
public void onViewCreated(View view, Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);
final String id = FirebaseAuth.getInstance().getCurrentUser().getUid();
search_keyword = getView().findViewById(R.id.exp_search);
search_btn = getView().findViewById(R.id.exp_search_btn);
ccp = getView().findViewById(R.id.exp_ccp);
refresh = getView().findViewById(R.id.refresh);
country = ccp.getSelectedCountryName();
setUpRecyclerViewInitial(country);
db.collection("Users").document(id).collection("preferences").document("event").get().addOnCompleteListener(new OnCompleteListener<DocumentSnapshot>() {
@Override
public void onComplete(@NonNull Task<DocumentSnapshot> task) {
if (task.isSuccessful()) {
DocumentSnapshot documentSnapshot = task.getResult();
if (documentSnapshot.exists()) {
String anime = documentSnapshot.get("anime").toString();
String art = documentSnapshot.get("art").toString();
String edu = documentSnapshot.get("edu").toString();
String gaming = documentSnapshot.get("gaming").toString();
String music = documentSnapshot.get("music").toString();
String other = documentSnapshot.get("other").toString();
String all = documentSnapshot.get("all").toString();
String search_key = search_keyword.getText().toString().trim();
country = ccp.getSelectedCountryName();
adapter.stopListening();
RebuildRecyclerView(country);
}
}
}
}).addOnFailureListener(new OnFailureListener() {
@Override
public void onFailure(@NonNull Exception e) {
}
});
adapter.setOnItemClickListener(
new ExplorePageAdapter.OnItemClickListener() {
@Override
public void OnItemClick(DocumentSnapshot documentSnapshot, int position) {
String id = documentSnapshot.getId();
Intent intent = new Intent(getActivity(),
event_customer_view_activity.class);
intent.putExtra("Event_ID", id);
startActivity(intent);
//   getActivity().finish();
}
}
);
}
private void setUpRecyclerViewInitial(String country) {
//.whereIn("type", Arrays.asList("Other"))
Log.e("explore frag",country);
Query query = Cref.whereEqualTo("country", country).orderBy("count", Query.Direction.ASCENDING);
FirestoreRecyclerOptions<POJO_explore_page_item> options = new
FirestoreRecyclerOptions.Builder<POJO_explore_page_item>()
.setQuery(query, POJO_explore_page_item.class).
build();
adapter = new ExplorePageAdapter(options);
RecyclerView recyclerView = getView().findViewById(R.id.explore_recycler);
recyclerView.setHasFixedSize(true);
recyclerView.setLayoutManager(new LinearLayoutManager(getActivity()));
recyclerView.setAdapter(adapter);
}
private void RebuildRecyclerView(String country) {
//.whereIn("type", Arrays.asList("Other"))
Log.e("explore frag",country);
Query query = Cref.whereEqualTo("country", country).orderBy("count", Query.Direction.ASCENDING);
FirestoreRecyclerOptions<POJO_explore_page_item> options = new
FirestoreRecyclerOptions.Builder<POJO_explore_page_item>()
.setQuery(query, POJO_explore_page_item.class).
build();
adapter = new ExplorePageAdapter(options);
adapter.startListening()
RecyclerView recyclerView = getView().findViewById(R.id.explore_recycler);
recyclerView.setHasFixedSize(true);
recyclerView.setLayoutManager(new LinearLayoutManager(getActivity()));
recyclerView.setAdapter(adapter);
}
@Override
public void onStart() {
super.onStart();
adapter.startListening();
}
public void onResume() {
super.onResume();
adapter.startListening();
}
@Override
public void onDestroy() {
super.onDestroy();
adapter.stopListening();
}